Comment by bornfreddy
1 year ago
I wanted to like Rust (memory safety and performance - what's not to like?) but both of my experiments with it ended in frustration. It seemed a way too complex language for what I needed.
Recently, a coworker of mine made a great observation that made everything clear to me. I was looking for a replacement for C, but Rust is actually a replacement for C++. Totally different beast - powerful but complex. I need to see if Zig is any closer to C in spirit.
> I was looking for a replacement for C, but Rust is actually a replacement for C++. Totally different beast - powerful but complex.
I've seen this sentiment a lot, and I have to say it's always puzzled me. The difference between Rust and basically any other popular language is that the former has memory safety without GC†. The difference between C++ and C is that the former is a large multi-paradigm language, while the latter is a minimalist language. These are completely different axes.
There is no corresponding popular replacement for C that's more minimalist than Rust and memory safe.
† Reference counting is a form of garbage collection.
Board games and craft beers are utterly unrelated objects who have commonality on essentially no axes (except sitting on tables, I guess). And, yet, if you like one, there's a very good chance you like the other.
I think that's where the sentiment comes from. It's not that Rust is similar to C++ in terms of the actual languages and their features. It's that people who like C++ are morely likely to like Rust than people who like C are.
I would argue that C is not a minimalistic language either. There is a lot under the hood in C. But it feels small in a way that Rust and C++ don't.
I think Rust and C++ appeal to programmers who are OK with a large investment in wrapping their head around a big complex language with the expectation that they will be able to amortize that investment by being very productive in large projects over a large period of time. Maybe sometimes the language feels like trying to keep a piece of heavy duty machinery from killing you, but they're willing to wrestle with it for the power you get in return.
The people who are excited about Zig and C wants something that feels more like a hand tool that doesn't demand a lot of their attention and lets them focus on writing their code, even if the writing process is a little more manual labor in return.
> And, yet, if you like one, there's a very good chance you like the other.
Among my friends I know several people who are very enthusiastic about board games and several who are very enthusiastic about craft beer, but there's not a particular noticeable overlap. Personally of course I am very into board games and I don't drink at all.
> I would argue that C is not a minimalistic language either. There is a lot under the hood in C.
Nah, C actually is small, that's why K&R is such a short book. It makes enormous compromises to pull that off, but presumably on a machine where 64kB of RAM is extraordinary these compromises made lots of sense. C23 is quite a bit bigger, for example "bool" is now an actual type (albeit implicitly convertible) but still small by modern standards.
There really isn't that much "under the hood", it's often just the least possible moving parts that could possibly have worked.
a[b] in C++ is a call to a member function a.operator[](b) -- arbitrary user code
a[b] in Rust is a call to core::ops::Index::index(a, b) or, in context IndexMut::index_mut -- again, arbitrary user code
a[b] in C is just a pointer addition of a and b - one of them will be converted to a pointer if necessary, and then the other one is added to the pointer using normal pointer arithmetic rules
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Exactly. There are two kinds of programmers, those who enjoy spending a bunch of time thinking about problems and decisions the language has foisted upon you (subtyping hierarchies, lifetime annotations, visibility, design patterns) and there are those that like spending that time thinking about the actual problem they want to solve instead.
I jest, but only a tiny bit. The features of heavy OOP and feature-rich languages tend to show their value only in really large codebases being worked on by several different people—precisely because many of their features are just guardrails to make it hard for people to code incorrectly against another's understanding or assumptions, when shared understanding is more difficult to establish. Contrarily, any solo programmer or really small team is almost invariably better served by a language like go, C, scheme, or Zig.
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> Maybe sometimes the language feels like trying to keep a piece of heavy duty machinery from killing you, but they're willing to wrestle with it for the power you get in return.
It's funny because to me there's an analogy with heavy machinery but materially different: there are some industrial machines that have two buttons that need to be actuated to activate the mechanism, separated by arm length in order to ensure that the operator's arms are out of the way when the limb crunching bits are moving. I see Rust that way, engineering the safe way to do things as the path of least resistance, at the cost of some convenience when trying to do something "unsafe".
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The reason I focus on the memory safety difference is precisely to not minimize its importance. It's far more salient of a difference than whether a language "feels big" or not. Talking about whether Zig requires "a little more manual labor" than Rust is missing the enormous elephant in the room.
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Today all of the code I'm not paid to write is in Rust. I spent many happy years previously getting paid to write C (I have also been paid to write Java, PHP, Go and C#, and I have written probably a dozen more languages for one reason or another over the years but never as specifically a thing people were paying me to do)
I always thought C++ was a terrible idea, from way before C++ 98, I own Stroustrup's terrible book about his language, which I picked up at the same time as the revised K&R and it did nothing to change that belief, nor have subsequent standards.
However, I do have some sympathy for this sentiment about Rust being a better C++. Even though Rust and C++ have an entirely different approach to many important problems the syntax often looks similar and I think Zig manages to be less intimidating than Rust for that reason if you don't want that complexity.
Personally I had no interest in C++† and I have no serious interest in Zig.
† Ironically I ended up caring a lot more about C++ after I learned Rust, and most specifically when understanding how Rust's HashMap type works, but I didn't end up liking C++ I just ended up much better informed about it.
It is not about memory safety or anything like that. It is about simplicity.
If you say "you can't do x with y in C++" you will get an "yes you can, you just use asd::dsadasd::asdadqwreqsdwerig_hfdoigbhiohrf() with weaorgoiawr flag". From what I have seen from Rust, it is similar. I don't want to fill my brain with vim bindings.. cough.. Rust ways of doing something. I just want to code my hobby game engine v7.
That said, I am happy to use software written in it. Even though the evangelists can be really annoying.
> † Reference counting is a form of garbage collection.
I agree with Raymond Chen's take on the academic definition of GCs[1], and therefore Rust is certainly a GC'd language (because your code behaves as though memory is infinite... usually). It's probably one of the first examples of "static garbage collection" - though I'm sure someone will point out a prior example.
[1]: https://devblogs.microsoft.com/oldnewthing/20100809-00/?p=13...
This feels like deliberate misdirection, because in most practical cases what people mean is "some memory management process that will slow my program down non-trivially". By this definition Rust does not have GC whereas Go, eg, does.
The "simulates infinite RAM" is an interesting perspective but simply not the subject of most conversations.
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By this logic you're writing the garbage collector by hand in C.
> There is no corresponding popular replacement for C that's more minimalist than Rust and memory safe.
In the real world, memory safety is not all-or-nothing (unless you're willing to concede that Rust is not safe either, since unsafe Rust exists). I'm working on an embedded project in Rust and I'd MUCH rather be using Zig. The only safety thing that Rust would give me that Zig does not is protection from returning pointers to stack-allocated objects (there are no dynamic allocations and no concurrency outside of extremely simple ISRs that push events onto a statically allocated queue). But in exchange I have to deal with the presence of unsafe Rust, which feels like a gigantic minefield even compared to C.
protection from returning stack pointers seems to be detectable with static analysis of zig AIR.
https://github.com/ityonemo/clr
> But in exchange I have to deal with the presence of unsafe Rust, which feels like a gigantic minefield even compared to C.
I think idiomatic coding norms for unsafe Rust are still a bit half-baked, and this is where something like Zig can have an advantage of sorts. You can see this also, e.g. in the ongoing proposals for a Pin<> alternative.
The similarity between C++ and Rust is that both bust your balls with complexity for programming at large. And the inverse goes for C and Zig.
Those are the axes relevant to the parent in the context of their comment - not specific language semantics or core features.
> > I was looking for a replacement for C, but Rust is actually a replacement for C++. Totally different beast - powerful but complex.
> The difference between Rust and basically any other popular language is that the former has memory safety without GC†. The difference between C++ and C is that the former is a large multi-paradigm language, while the latter is a minimalist language. These are completely different axes.
Indeed. Let one axis be the simple/multi paradigm. Let the other axis be no memory management / automatic memory management without GC / GC. This divides the plane into 6. In the simple + no memory management sits C and Zig, and in the multiparadigm + memory safe without GC segment sits C++ and Rust.
> There is no corresponding popular replacement for C that's more minimalist than Rust and memory safe.
Those are some weird requirements for "being a replacement", but it is obviously true, as you picked them such.
It's not a perfect analogy, but if you want to put yourself in the shoes of the people making it:
1. Rust is an immensely complicated language, and it's not very composable (see the async debacle and whatnot). On the simple<->complex slider, it's smack dab on the right of the scale.
2. Ignoring any nitpicking [0], Zig is memory-safe enough in practice, placing it much closer to Rust than to C/C++ on the memory safety axis. My teammates have been using Zig for nearly a year, and the only memory safety bug was (a) caught before prod and (b) not something Rust's features would have prevented [1]. The `defer` and `errdefer` statements are excellent, and much like how you closely audit the use of `unsafe` in Rust there is only a small subset of Zig where you actually need to pull your magnifying glass out to figure out if the code has any major issues. In terms of memory issues I've cared about (not all conforming to Rust's narrow definition of memory safety), I've personally seen many more problems in Rust projects I contribute toward (only the one in Zig, plus a misunderstanding of async as I was learning the language a few years ago, many of varying severity in Rust, at this point probably more code written in Zig than Rust, 10yoe before starting with either).
With that in mind, you have C/C++ on the unsafe axis and Zig/Rust on the safe axis. The complexity axis is self-explanatory, fleshing out the analogy.
Is Zig memory-safe? No, absolutely not. Does that mean that Rust will win out for some domains? Absolutely. In practical terms though, your average senior developer will have many memory safety bugs in C/C++ and few in Zig/Rust. It's a reasonable way to compare and contrast languages.
Is it a perfect description? No, the map is not the territory. It's an analogy that helps a lot of people understand the world around them though.
[0] Even Python is simpler than Rust, and it's memory-safe. If we're limiting ourselves to systems languages, you still have a number of options like Ada and Coq. Rust is popular because it offers a certain tradeoff in the safety/performance/devex Pareto curve, and because it's had a lot of marketing. It's unique in that niche, by definition, but it's far from the only language to offer the features you explicitly stated.
[1] It was just an object pool, and the (aggregate) resetting logic wasn't solid. The objects would have passed through the borrow checker with flying colors though.
Edit: To your GC point, many parts of Rust look closer to GC than not under the hood. You don't have a GC pause, but you have object pools (sometimes falling back to kernel object pools) and a variety of allocation data structures. If RC is a GC tactic, the extra pointer increment/decrement is negligible compared to what Rust actually does to handle its objects (RC is everything Rust does, plus a counter). That's one of my primary performance complaints with the language, that interacting with a churn of small objects is both expensive and the easiest way to code. I can't trust code I see in the wild to behave reasonably by default.
> see the async debacle and whatnot
The async featureset in Rust is far from complete, but async is also somewhat of a niche. You're not necessarily expected to use it, often you can just use threads.
> Zig is memory-safe enough in practice
Temporal safety is a huge deal, especially for the "programming in the large" case. Where unstated assumptions that are relied upon for the safety of some piece of code can be broken as some other part of the code evolves. The Rust borrow checker is great for surfacing these issues, and has very few practical alternatives.
> If we're limiting ourselves to systems languages, you still have a number of options like Ada and Coq.
It's easy to be "safe" if the equivalent to free() is marked as part of the unsafe subset, as with Ada. Coq is not very relevant on its own, though I suppose it could be part of a solution for proving the memory safety of C code. But this is known to be quite hard unless you do take your care to write the program in the "idiomatically safe" style that a language like Rust points you to.
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I've been seeing C++ fans talk about how they never see memory safety issues in practice in C++ for a decade and a half. I even believed it sometimes. But if there's ever been a common story over those 15 years, it's that these anecdotes mean little, and the actual memory safety property means a lot.
The only time I've seen "almost memory safe" actually work is in Go and Swift, which have memory safety problems with concurrency, but they're actually rare enough not to matter too much (though in Go's case it would have been easy to design interfaces and slices not to have the problem, and I wish they had). I simply don't believe that Zig is meaningfully more memory safe than C++.
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> On the simple<->complex slider, it's smack dab on the right of the scale.
Sure, but now you snuck in an Artifact of Death (in TvTropes sense) into your codebase. It won't kill your code base immediately and with proper handling it might work, but all it takes is one mistake, one oversight, for it to cause issues.
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> 1. Rust is an immensely complicated language, and it's not very composable.
It is a procedural language and as such, composition of functions is not implemented easily, if at all possible. It is a shame for sure that such powerful techniques are not possible in Rust, but for some people it is worth the trade off.
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even so it seems like it would eventually be possible to do more safety analysis for zig, if not in the compiler itself:
https://github.com/ityonemo/clr
> There is no corresponding popular replacement for C that's more minimalist than Rust and memory safe.
There is Objective-C, it fits your definition of memory safety.
Objective-C and Swift are the reason why I added the footnote. (Also Objective-C is very, very much not memory safe.)
From what I understand that language is Zig, no?
Also, there's FORTH!
I don't think Zig is memory safe?
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This is actually accurate. While Rust is a great replacement for C, so is C++. But Rust has tons of extra features that C doesn't have, just like C++. Moving from C++ to Rust is a sideways move. Moving from C to Rust is definitely an increase in complexity and abstraction.
Rust is a great replacement for C++ as it fits into the same place in the stack of tools.
Go is not a C or Python replacement.
Zig is a good replacement for C.
> Go is not a C or Python replacement.
Google stopped writing new Python, because they found that the same engineers would produce software with similar defect rates, at a similar price and in similar time, with Go, but it would have markedly better performance, so, no more Python.
Go manages to have a nice sharp start, which means there are going to be a bunch of cases where you didn't need all the perf from C, but you did need a prompt start, so, Java was not an option but Go is fine.
In my own practice, Rust entirely replaces C, which has previously been my preferred language for many use cases.
> But Rust has tons of extra features that C doesn't have, just like C++.
C++ has tons of extra features over C because it's a kitchen sink language. Rust has some extra features over C because in order to support static analysis for memory safety in a practically usable manner, you need those features. In practice, there are lots of C++ features that Rust doesn't bother with, especially around templates. (Rust just has a more general macro feature instead. The C++ folks are now on track to adding a clunky "metaclass" feature which is a lot like Rust macros.)
Every language becomes a kitchen sink with enough time on the market, even C, people really should learn about the standard and the myriad of compiler extensions, K&R C was almost 60 years ago.
C++ already has almost Rust macros, with a mix of compile time execution, concepts and traits, without requiring another mini-language, or an external crate (syn).
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I've used Rust quite a bit now and there are too many features. It can't claim to be tidy anymore. Sure it's a better situation than C++, but it is getting worse and unlikely to get better.
> Moving from C++ to Rust is a sideways move.
In what sense? Features or complexity? From a productivity/correctness perspective, Rust is a huge step up over C++.
While I agree, that isn't much the case for those using static analysis, and hardened runtimes, which provide much of the same safety improvements, granted without lifetimes tracking.
Use more xcode, Clion, Visual Studio, C++ Builder, and less vi and Emacs for C and C++.
Not everyone has the RIIR luxury for what we do.
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> Zig is a good replacement for C.
I have never used zig, although I have looked into it. I have used C and C++ for a long time, and would like a replacement for C.
To my mind zig is nowhere near a good replacement for C. It adds way too much extra stuff (e.g. metaprogramming). A good replacement for C would have a similar simplicity and scope to C (i.e. a portable assembler) but address known issues. For example it should fix the operator precedence rules to be sane. It should close-off on undefined behavior and specify things more formally than C, and still allow low-level memory manipulation. To be even better than C it should allow stuff that would be obviously correct in assembler, but is UB or ID in C.
Go has plenty of bad design decisions, but not being a safer C isn't one of them.
TinyGo and TamaGo folks enjoy writing their bare metal applications on embedded and firmware.
Somewhat related, even when I work with C++ I use it as "C with RAII". What I actually want is a scheme (R5RS) with manual memory management and a borrow checker. I don't know how well such a monstrosity would actually work in practice, but it's what I've convinced myself that I want.
https://github.com/carp-lang/Carp
posted yesterday:
https://news.ycombinator.com/item?id=42923829
>"but Rust is actually a replacement for C++. "
I would disagree. C++ provides way more features than Rust and to me Rust feels way more constrained comparatively.
Sure, in the sense that in C++ they've got the Head Of Vecna: https://rpgmuseum.fandom.com/wiki/The_Head_of_Vecna
Many of my favourite Rust features aren't in C++. For example they don't have real Sum types, they don't have the correct move semantic, they are statement oriented rather than expression oriented and their language lacks decent built-in tooling.
But also, some of the things C++ does have are just bad and won't get fixed/ removed because they're popular. And there's no sign of it slowing down.
I think that in practice you should use Rust in most places that C++ is used today, while some of the remainder should be WUFFS, or something entirely different.
>"I think that in practice you should use Rust"
I am doing fine. Thank you. Also I am not a language warrior. I do have my preferences but use many since I am an independent and work with many clients.
The biggest issue for me, is that Rust isn't used where I care about, mainstream language runtimes, compiler toolchains, and GPU ecosystem standards.
No one from them would accept a patch in Rust instead of C or C++.
Yes I know about Deno, but even them haven't rewriten V8, and wgpu or Rust CUDA aren't the same as what Khronos, NVidia, AMD, Microsoft put out in C++.
> Rust is actually a replacement for C++
Last I checked, rust touted itself as a systems programming language, which C++ kinda is but mostly isn't (many C++ features just aren't appropriate or are poorly suited for systems programming).
I would never choose Rust over C++ for scientific programming, because Rust metaprogramming features are so poor.
However I'd probably choose Rust over C in many areas where C is best suited.
So to me the venn diagram of utility shows Rust to overlap with C far more than C++.
I read a blog that called Rust a language that was aimed to be high-level but without GC.
My experience with Zig is that it's also a plausible replacement for C++
explanation needed, bro.
nerdy langnoob or noobie langnerd here. not sure which is which, cuz my parsing skills are nearly zilch. ;)
Zig’s comptime feature gives a lot of the power of C++ templates. This makes it easier to implement a lot of libraries which are just a pain to do in plain C. Even seemingly simple things like a generic vector are annoying to do in C, unless you abandon type safety and just start passing pointers to void.
I believe Zig even has some libraries for doing more exotic things easily, such as converting between an array of structs and a struct of arrays (and back).
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C programmers have long suffered the cumbersome ritual of struct manipulation—resorting to C++ merely to dress up structs as classes.
Zig shatters that with comptime and the 'type' type.
[flagged]
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